Electromagnet switch



Oct. 3, 1933. G GILLEN 1,928,722

ELECTROMAGNET SWITCH Filed Jan. 25, 1932. 2 Sheets-Sheet l 13 earye Z ffwa G. A. GILLEN Oct. 3, 1933.

ELECTROMAGNET SWITCH Filed Jan. 25, 1932 2 Sheets-Sheet 2 Z4 Z3 Z0 J VEWQGF MIT Patented Oct. 3, 1933 PATENT OFFICE ELECTROMAGNET SWITCH George A. Gillen, Bronx, N. Y., assignor to Oakes Products Corporation, North Chicago, 111., a corporation of Michigan Application January 25, 1932. Serial No. 588,729

3 Claims.

My invention relates to electromagnet switches and covers an improved switch of the solenoid type adapted for general use but particularly adaptable for controlling the circuit for the en- 'gine starting motorin an automatic hydrocarbon starting system.

An important object of the invention is to provide a compact structure in which the circuit 3 closing switch members are capable of carrying heavy current flow and are arranged concentrically within the solenoid winding for relative movement to close the circuit upon current flow through the solenoid winding.

A further object is to provide an arrangement in which one-of the switch elements has a floating or yielding support so that it may adapt itself for intimate engagement and contact with the other switch element in order to insure contact .engagement of the least resistance and of maximum contact area so as to eliminate arcing.

The various features of my invention are incorporated in the structure disclosed on the drawings, in which drawings:

, Figure 1 is a side elevation of the switch struc- 2 ture;

Figure 2 is an end elevation;

Figure 3 is an enlarged section on plane IIIIII of Figure 1;

;. Figure 4 is an enlarged section of a contact 30 supporting ring and contact member;

Figure 5 is a section of the ring on plane VV of Figure 4; r

Figure 6 diagrammatically illustrates the switch structure and its inclusion in a starting circuit for 35v an automotive engine.

The structure shown comprises a supporting plate 10 which may be of rectangular shape and whose lower end is deflected. outwardly to form a supporting flange or base 11 by means of which the structure may be mounted on a suitable support. The base 11 maybe curved longitudinally to saddle over a cylindrical support as for examme the starting motor of an automotive engine.

, Theends of the flange may have hooks 12 for receiving the ends of a strap 13 for extending around the support to hold the structure rigidly and detachably in place.

On the inner side of the wall 10 is the cylindrical cup-shaped housing or shell 14 having the flange 15 for seating against the wall 10. At the outside of the wall 10 is a plate 16 having the cylindrical projection or head 1'7, bolts 18 serving to detachablyrigidly secure the wall 10 and the plate 16 and the flange 15 together, with the shell 14 and cap 17 concentric.

The wall 10 has the opening 19 concentric with the shell 14 and a stationary core member 20 has the neck 21 extending through the opening 19 and being burred out so as to rigidly secure the core member to the Wall, insulating material 22, such as mica, being inserted to insulate the core member from the wall.

Within the shell 14 is a spool 23 of suitable insulating material such as so-called bakelite and this spool supports a winding or coil 24. The stationary core member 20 fits into the bore of the spool at one end thereof and in the other end of the spool bore is a movable core member 25, nor mally spaced away from the stationary core member 20 but attracted thereto when current flows through the coil 24. The stationary core member 20 has the cylindrical bore 26 through which projects the cylindrical bar 27 of good current conductive material such as copper and outside of the wall 10 this bar has the head 28 terminating in a conical end 29, an insulating and cushioning washer 30 being interposed between the head 28 and the end of the core member 20.

The movable core member 25 has a cylindrical bore receiving at its outer end the reduced end 27 of the bar 27, the inner end of the bore being of enlarged diameter to forma pocket 31. a spring 32 encircling the bar to abut at one end against the core member 25 at the base of the pocket 31 and at its other end against the inner end of the stationary core member 20, the spring tending to keep the core members normally separated to leave an air gap between them. The outer end of the bar 27 is threaded to receive a nut 33 between which and the shoulder 34 of the bar the core member 25 is clamped so that the bar must move with this core member when the core member is shifted toward the stationary core member uponcurrent flow through the coil 24. The core members are of good magnetic material such as Swedish iron and the bar 27 forms a movable current conducting switch member.

At its outer end the housing shell 14 has the cylindrical neck 14' with the opening 35 through its outer wall. The neck 14' is lined by a bushing 36 of insulating material and has the neck 37 extending outwardly through the opening 35. A terminal pin 38'extends outwardly through the neck 3'7 with its head 39 engaging against the inner wall of the bushing 36 and being threaded at its outer end to receive a nut 40. An insulating washer 41 surrounds the neck 37 of the bushing outside of the shell 14 and between this washer and the nut a metal washer 42 is inserted so that when the nut is screwed up the shell 14 will be clamped between the nut and its head 39. Another nut 43 may be applied on the threaded end of the pin so that circuit conductors may be secured to the pin. A clip 44 is inserted under the head 39 of the pin and a clip 45 inserted between the nut 33 and the core member 25, a flexible conductor 46 connecting the clips so that the terminal pin 38 will be in electrical engagement with the switch bar 27, the flexible conductor permitting free movement of the switch bar in response to current flow through the coil 24 or the pressure of the spring 32. Current flow through the coil will cause the movable core member 25 to be attracted toward the stationary core member 20 to shift the switch bar 2'7 outwardly and upon opening of the energizing circuit the spring 32 will retract the movable core member and switch bar.

Terminal pins 47 and 48 are secured to the outer head of the spool 23 and extend outwardly through openings 4.9 in the end wall of the shell 14, the pins being insulated. from the shell by insulating bushings 50. Nuts 51 clamp the pins in rigid position and at their inner ends the pins 47 and 48 are connected with the ends of the energizing coil 24, the energizing circuit for the coil being connected with the pins at their outer ends.

In the outer end of the extension 17 on the plate 16 is a bushing 52 of insulating material whose neck 53 extends through the opening 54 in the outer wall of the extension. Extending through this neck is a terminal pin 55 whose head 56 engages the outer wall of the bushing 52. An insulating washer 57 surrounds the outer end of the neck 53 and a washer 58 engages the insulating washer and serves as an abutment for the nut 59 engaging the threaded end of the pin whereby the pin is securely clamped to the extension 17. Another nut 60 may be provided on the pin so that circuit conductors may be secured to the pin.

At the inner end of the extension 17 is the insulating bushing 61 between which and the bushing 52 is a ring 62 of insulating material which forms a support for the switch element 63 which is cylindrical and at its inner end has the conical pocket 64 shaped to accurately receive the conical end 29 of the movable switch bar 27. At its outer end and at diametrally opposite points the ring 62 has the notches 65 and 66 for receiving the ends of a pin 67 extending through the diametral passageway 68 through the switch member 63 near the outer end thereof. The diameter of the switch member 63 is slightly less than the inner diameter of the ring 62 and the passageway 68 is of slightly larger diameter than the diameter of the pin 67, and the pin ends fit loosely in the slots 65 and 66 so that the switch member .63 is yieldably supported or "loats in the ring 62. The ring 62 abuts against the inner end of the bushing 52, which bushing closes the outer ends of the slots 65 and 66 so that movement of the pin longitudinally in the slots is limited by the length of the slots. With this floating support for the switch member 63 the member may move to adjust its position for accurate reception and seating in its end 64 of the conical end 29 of the switch bar 27, accurate and uniform contact over the entire contact surface of the switch member being thus at all times assured with minimum resistance contact over maximum contact surface.

A flexible conductor 69 is secured to the outer end of the switch member 63, its other end being secured to a clip 70 clamped below the head 56 of the terminal pin 55. This flexible conductor does not interfere with the free floating movement of the switch member 63.

In Figure 6 I diagrammatically show the use of my improved switch structure in an automatic starting system for a hydrocarbon engine. One terminal of the vehicle battery 71 is grounded and the other terminal is connected by the conductor 72 with the switch member 63, the electrical connection being made through the terminal pin 55. The movable switch member 27 is connected through the terminal pin 38 with the conductor 73 leading to one terminal of the engine starting motor 74 whose other terminal is grounded. The energizing circuit 75 extends from the battery 71 and includes the energizing winding 24 of the switch structure andthis energizing circuit includes a switch 76, which may be the ignition switch for the engine ignition system, and the circuit may also include a governor structure 77 driven directly or indirectly by the engine and operable to open theenergizing circuit 75 while the engine is at rest or is being started by the starting motor, and to open the circuit as soon as the engine has been started and is running. When the switch 76 is closed the circuit 75 is closed and the winding 24 receives current flow and the movable core member 25 is attracted to the stationary core member 20 so that the switch member 27 will be shifted to engage its conical head in the conical socket of the floating switch member 63 and the circuit will be closed through the starting motor 74 and the engine will be started. As soon as the engine has been started, and is running, the governor 77 opens the circuit 75 whereby the switch may be energized and spring 32 will shift the movable core and the switch member 27 back to normal position and the starting circuit is opened. Should the engine stall unknown to the driver the governor 77 will automatically reclose the circuit 75 and the switch will again operate to close the starting circuit for restarting of the engine.

The switch elements 27 and 63 are of good conductive material such as copper and are of ample proportion so that they will carry large current flow without heating. The extensive conical surfaces at the ends of the switch members will uniformly and intimately engage over their entire area when the switch is energized, on account of the floating support of the member 63. Should by chance the contact surfaces become frozen together at any point for any reason, the floating member 63 will cant under pull of the spring 32 and any adhesion between the surfaces will be readily and easily broken so that the spring may restore the movable switch member 27 to normal position to open the starting circuit.

I have shown a practical and efiicient embodiment of the various features of my invention but I do not desire to be limited to the exact structure, arrangement and operation shown and described as changes and modifications may be made without departing from the spirit of the invention, as defined in the appended claims.

I claim as follows:

1. An electrical switch comprising an energizing coil, a core movable in said coil in response to current flow therethrough, a switch bar movable with said core and having a contact end, a supporting frame adjacent to the end of said switch bar, a contact member loosely located in said frame and having a contact surface for receiving the contact end of said bar, and a pin extending through said contact member and having loose engagement therewith and loose engagement at its ends with said supporting frame whereby said contact member may have limited universal movement in said frame whereby said contact member when engaged by the switch bar contact end may align itself for intimate and uniform engagement of its contact surface with the switch bar contact end.

2. A solenoid switch structure comprising a solenoid coil, a stationary core member within one end of said coil and a movable core member within the other end of said coil, means normally separating said members, a cylindrical switch bar extending through the stationary core member to be guided thereby and connected with the movable core member for movement therewith during current flow through said coil, said movable switch bar having a solid'conical head, a solid contact block having a conical pocket opposed to the conical head of said switch bar, and means supporting said contact block for limited universal movement whereby it may be accurately aligned when engaged by said switch bar head to cause uniform and intimate engagement between the conical surfaces.

3. An electrical switch comprising a cylindrical shell, an energizing coil within said shell, a stationary core within the outer end of said coil having a guide passageway therethrough, a movable core within the inner end of said shell, a bar of non-magnetic but electrically conductive material secured at its inner end to said movable core and extending through said guide passageway, the outer end of said bar having a solid conical contact head, a contact block supported for limited universal movement adjacent to the contact head and having a conical socket for receiving said head when said bar is shifted outwardly by said movable core during current flow through said coil, a circuit terminal on the inner end of said shell concentric with said bar and electrically connected therewith, and a circuit terminal at the outer end of said shell concentric with said bar and having electrical connection with said block.

GEORGE A. GILLEN. 

